Machine for computing interest.



No, 819,667. PATENTBD MAY 1, 190a.

0. A. MARBLE. MACHINE FOR COMPUTING INTEREST.

APPLIGAYHON FILED JAN. 4, 1905.

7 SHEETS-SHEET 1.

No. 819,667. PATENTED MAY 1, 1906.

G. A. MARBLE. MACHINE FOR COMPUTING INTEREST.

APPLICATION FILED JAN.4,1905.

7 SHEETS-SHEET 2,

WITNESSES:

ATTORNUS PATENTED MAY 1, 1906,

v 0. A. MARBLE. MACHINE FOB COMPUTING INTEREST.

APPLICATION FILED JAN.4,1905.

7 SHEETSSHEET 3,

. WITNESSES:

bX WW BY '7 Z I I ATTORNEYS No. 819,667. PATENTE-D MAY 1, 1906 O. A. MARBLE.

MACHINE FOR COMPUTING INTEREST. APELIGATION FILED JAN.-1,1906.

7 SHEETS-SHEET 4,

N0. 819,667. PATENTED MAY 1, 1906.

- 0. A. MARBLE.

MACHINE FOR COMPUTING mmmsr APPLICATION TILED JAN. 4, 1905.

7 SHEETS-SHEET 5 Arron/ms PATENTBD MAY 1 1906.

0. A. MARBLE. ma ma FOR COMPUTING INTEREST.

APPLICATION YILED JAN.&, 1905.

7 SHBETSSHEET 6 INVENTOR man/mg fit? CHARLES ABLE MARBLE, OF OTTUMl/VA, IOl/VA.

MACHINE FOR GQMPUTBNG ENTEREST.

Eipecification of Letters Patent.

I Patenteu May 1, 1906.

Application filed January 4.1905. Serial No- 289.560.

.10 101.11 lbll' lllll [I 771/07 (10721067711;

Be it known that I, CHARLES ABLnMAm' BLE, a citizen of the United States, residing at Ottumwa, in the county or Wapello and State of Iowa, have made certain new and useful Improvements in Machines for Computing Interest, of which the following is a specification.

My invention is an improvement in the class of automatic calculating-machines, more especially such as'are particularly adapted for computing interest.

The 0 sets I have had specially in view in devising and constructing the machine are comparative simplicity, great durability and facility, and absolute accuracy of operation.

A'principal feature of my machine is a series of rotatable members, each comprising nine rollers, arranged parallel around a common axis and each inscribed on its periphery with numbers indicating different amounts of interest on a given sum for a given time. These several rollers have a planetary motionthat is to say, each. is rotatable on its own axis and bodily around the common central axis. In view of the construction and arrangement of the aforesaid membersthey may be conveniently designated in description as multiple-roller cylinders or for still greater brevity multiple cylinders. The means for rotating or adjusting, locking, and releasing these members or. cylinders as a whole and their individual component rollers further embody special features of my invention.

The multi le cylinders are arranged parallel horizontally and in the same vertical plane. Another special feature is the provision of a series of apertured slides arranged vertically in front of the several multiple cylinders and serving to expose on the inscribed rollers in the required manner the several amounts of interest that are sought in any special computation. These slides are operated-i. e., pulled down-to expose numbers indicating amounts of interest by means oi a rotatable roller or cylinder having teeth adapted for detachable engagement successively with the said slides. The toothed cylinder is conveniently rotated by a handwrank, and this is t e sole manual manipulation required to obtain the interest amount or amounts sought, save the preliminary setting or adjusting of certain devices which are in the nature of sliding indicators relating to rate or per cent.

and also illustrating the means for of interest and the amount or sum upon which I such interest is to be computed.

My invention also, includes other features or mechanism involving novelty and which are important in connection with those above referred to. j. i

The construction, arrangement,=and 0. 'er-. ation of parts are as hereinafter deseri ed, reference being had to the accompanying drawings, in which' Figure 1 is a front elevation of my 'comput in'g-machine, a portion of the casmgbeing broken away 'to show the interior construction and arrangement of certain parts. Fig. 2 is in part a front elevation, the casing bein broken away to further illustrate the interior construction. Fig. 3 is a vertical transverse section of the machine, the line ofsecti'on being near the left-hand end ofthe casings. Fig. 4 is an end view of one of the multiple-roller cylinders, a portion of the master-gearwhich engages and rotates the several rollers being partly broken away. Fig. 5 is across-section of one of the multiple-roller cylinders. T Fig. 6 is a transverse section of a ortion of the front of the casing of the mac line/showing the arrangement of the :vertical' 3 ertured slides with relation to said casingf. ig. 7 is a vertical cross-section of the lower portionv of the machine. Fig. 8 is a perspective view of the lower portion of the rack, Which'is conof the machine and serves toad'ust all the rollers of the several cylinders to lndicate interest or per cent. Fig. 9 is aperspective view of a portion of one of the apertured slides. Fig. 10 is a vertical cross-section of the machine, showing the interest -rackconnected with the gears, which serve to rotate the several rollers of the cylinders for indicate 111g interest.

nected with the interest-indicator on the front. I

Fig. 11 is a vertical section of the right-hand portion of the machine, show:

ing the connection and arrargement of parts whereby the rollers of the multiple cylinders are adjusted for indicating interest and princifpal Fig. 12 is a vertical transverse section 0 the machine, taken near the right-hand end of the casing and illustrating the arrangement of the racks for adjusting or rotating the multiple-roller cylinders to indicate the principal upon which interest is to be the racks vertically. Fig. 13 is a tical section of a portion of the front of the casing, showing one of the covers or shupters 'it I] computed adjusting detail veri I Ft 4 I cylinders. slg. is is a detail section illustra mg the arrangement of a sprin conion with one of the multiple-roller eylintiers and the master-gear by which. the several s 5 rollers of such cylinders are rotated. 17

is a diagrammatic View showing in plan the entire faces or circumferences of the nine rollers forming a multiple-roller cylinder, the

rates of interest of different amounts at clil torrent per cents. being indicated on the rollers. Fig. 18, Sheet 2, is a sectional View illustrating the position or local relation of a roller of a multiple cylinder and an apertured slide with. reference to a slot in the casing '25 when. a number indicating interest can lie read on the roller.

Referring in the first instance to l ies. 1, 2,

and 3, 1 indicates a casing" which incloses most ol the operative parts, the some being prefergo aoly constructed of sheet metal. its ont side is provided with a series of parallel slots 2, 3, and -l,- (see Fig. 1,) which are spaced apart ,equidistontly and extend the length the multiple-roller cylinders which .5 are directly beyond them. It Will be seen that each multiple-roller cylinder is so arranged that its axis is in the some horizontal plane With one of the aforesaid slots. In the lower portion. or e rged base of the 0 sins l is eiranged the horizontal roller 5, (see Fig. 2 having a of teeth 6 arranged spirally thereon and provided With a crank 7, which is accessible at the lel'thand end of the casing. The be "ings of this roller are ar- H l in. two Vertical standards or plates 8 9, (see 1 and 2,) Which are located iort iiistance from the respective ends of easing. .o shown best in Fig. 3, a large sprocket- 0 is mounted on the shaft 5- of the and. s chain 11 runs thereon and also sprocket-Wheels 12, l3, end it, which ounted loose on the shafts of the re- ;sneetive nulltiple-rollm' cylinders, means he- 5 provided for locking them therewith is required to rotate the said cylin- Whole. The chain. 11 runs on oppoof the sprocket-Wheels 12, i3, and shown idlers 1.5 being arra? in (his 1 Zoo to guide the chain, as will be undo? stood by reference to Fig. 3. For convenience ol d nation the multiple-roller cylinders I oesignated by A, B, and C, the lower one, .45., being opposite the slot 2 in the casing 1', the cylinder 13 opposite the slot 3, and the U opposite the slot l. these a lIiLlGlfS are Dll'ftll"3ll i. merit l suitably jOlll standards .1 plates 8 :1 cylinders and the sh l are arranged to. ides 3. ing channeled lon Fl 's. 6 and J, and root l o, the so.

logs or eperi: vmich, r slnles prone may l:- tsin figures or numbers on "e roller.

cylinders i. and t. so slides (tad of metal, y sheet 11' struck up in the required .o;-.m,a=1d are :1

re god vertically side l" and supported be by :1. series of pi l 1?, {sec and 2,) Whic lj/ attached.

; are SLll cross-bar l8, arranged n the upper portion The nnrul l rode .l'langes or of the rising 1. etlges ol the "Weird Sill lit in. gl'UU M. formed in ther-mtol ll] f l 1 side of the samz, as slim may he "(.irlmd in the om up the l nt of the cy. slrncled oi sheet metal, casting the some, it the czm ng of thin cast metal, or they ill r l any other manner so long is kept in VlG\V---T!:HUQU', fixed guides for the Slldts operate properlv and be lv As shown lli J aforesaid slides l t M, an angular lever 20 i. i i

crowd in rs the main. purpose it; rovide verti al so that they ll of; lead} in place. each ol the -v connect ed with i pivoted to the n and extends horirear side of the e h 10o zontally toward the l'ront thereof. To the pendent free end of said hr is pivoted a catch 21, the some being :ul ed to one: one of the teeth 6 on the rot A spring .22 s eves lo pr r ch 2). o: word, so that ii is olv position for s engagement and is at l re s" 0 time odor/te l to yield outward or liodtr.

so that the or n he ed lmcln d without in. curly; o 1th the. email. nor side of catch is w swirled w th a sw l.

or rounded pro; 3, wnich in in contact With the sem /holy of the ler When the catch drown down. and t in i'reeir slnr nldcr of "we catch him tooth i2 id mongol. nected ith the upper o serve to hold the .le (21's 2!; normally in zontal position or with their outer ends n rings i 1, e.

i contact With a lnn'izcontal stop-bar 24. The

details of oper ther relcrr d t As before Julia zit-d, the spi'v l2, 13, and 14. are mounted lc shafts 26, and 27 of the r L 'on oi these parts will he in roinali'er.

h ol l ow 'iple cylinders 12., and site or l'lgllt-llz'lfml ends ol eversl si) i right from the vertical standard 9, in which they are journaled-that. is to say, the lower shaft projects farthest, the shaft 26 a less distance, and the shaft 27 the sl1ortest.dis tance. This is for the purpose of allowing due space for connection of the several shafts with the means for adjusting them as required to rotate the multiple cylinders as a whole for setting them to accord with the numbers indicating theprincipal upon which interest is to be computed. The several gears 28, 29, and 30 and the sprocket-wheels 12, 13, and 14 on left side of machine (see Figs. 1 and 3) are lockedby means of a rod 31. (See especially Figs. 14 and 15.) This rod is provided at its respective ends with lugs 32 33, the former being adaptedto engage one of the sprocketewheels and also the end of the adjacent hollow shaft, while the opposite lug 33 is adapted to engage one of the spur-gears 28, 29, and 30. As indicated in Figs. 14 and 15,- the several sprocketwheels 12, 13, and 14 are provided with notches 34 around the central openings there in, and the hollow shafts 25, 26, and 27 are provided with a notch 35, which the lug 32 is adapted to enten. Thus when the lockingrod 31 is adjusted to the left, as shown in Fig. 14, the lug 33 enters a notch in the adjacent gear 30 and locks it, While the opposite lug 32 is free from the sprocket-wheel on the opposite end of the hollow shaft 27. On the other hand, if the said rod 31 be shifted t9 the right the lug 33 will be disengaged from the gear, which will then be left free to rotate on.

the hollow shaft, while the lug 32 Will enter the notches 34 of the sprocket-Wheel and the notch 35 in the hollow shaft, and thus such sprocket-wheel will be locked with the shaft.

Since the multiple cylinders A, B, and C are each fast on their respective hollow shafts 25, 26, and 27, it is apparent that they will all be rotated bodily W en the rod 31 is locked with the SPI'OCkGtrWhGBlS 12, 13, and 14, as above described, and,-contrariwise, when the locking-rods 31 are disengaged from the 'srockets 12, 13, and 14 the multiple cyliners may be rotatedwithout affecting the sprocket-wheels or the cylinder 5, with which they are operatively connected through the mediumof the chain 11. The several spurgears 28, 29, and 30 engage vertical racks 28, 29, and 30, (see Figs. 2 and 1 1,) and by vertical adjustment of these racks the multiple cylindersare rotated bodily for setting them to indicate the amount of principal upon whichthe interest is to be computed, as will be further described. As indicated in Fig. '10, a rack-bar 36 en gages a series of spur-gears 37, 38, and 39, which are mounted loose and also slidable on the hollow shafts of the res ective multiple cylinders A, B, and C. As s iown in Figs. 14 and 16, the hubs of the spur-gears 37 39 are provided with a radial lug 40, which is adaptspur-gears 43.

Pll'llOIlS or small spur-gears are mounted fas I it ed to enter a corresponding notch 41, formed in a large spur-gear 42, which for convenience of description will be hereinafter termed the master-gear,, since it meshes with a series of concentrically-arranged pinions or'small (See Fig. 4.) These several on the shafts or journals of the nine rollers which constitute the main portion of each of the multiple cylinders A, B, and C. The said rollers are journaled so as to rotate free in circular hubs or disks 52 53, and the gears 43-51 are arranged exterior to the right-hand. disk 53. The said disks are mounted fast on the hollow shafts 25, 26, and 27, so as to rotate therewith when the said shafts are duly looked, as before intimated. The several gears 37,38, and 39 are slid, and thereby shifted on the hollow shafts of the multiple cylinders for bringing their hubs into and out of engagement with the several -master-gears 42 as required in the operation of the machine hereinafter described. ,For the purpose of thus shifting these gears I employ (see Fig. 10) a vertical rock shaft or rod 54, having lever-arms 55, the shaft being journaled on the back of the casing 1 and extending i nearly the height of the latter. The free ends of the lever-arms 55 are forked to adapt them for loose engagement with the hubs of the gears 37, 38 and 39, the hubs having a circumferential groove for this purpose. It will be observed in Fig. 10, also in Fig. 12, that all the racks are held in due engagement with the respe'ctive'gea'rs by means of brackets or rollers which work in connection with the backs of the rack.

In view of their functions I will hereinafter term the rack 36 the interest-rack, since it is used solel for adjusting the multiple cylinders or, rat er, the individual rollers thereof, as required ,to indicate some articular rate of interest or percentage, and will term the other racks 26 29, and 30 as amountracks or principal-racks, since their sole purpose'is to adjust the multiple cylinders as required to indicate the amount or principal upon which interest is to be computed.

Sinoein the present machine but three multiple cylinders A, B, and G are illustrated, it is obvious that three amount-racks areemployed, and they, as shown in Figs. 2 and 11, are duly spaced apart, and each of them is provided on the face of the casing 1 with knobs by which they are duly adjusted. The inter- Lil spur'gesrs 37, 38, and 39 of Ye multiple cylinders A, B, and Q Kl corrcsuondingl 'lhusiithe knob so we adj :sted so that it opposite the 1mm her G on the adjacent scale the will rotate the gears ill-0'9, and througlrthe i i EStltbliSllfll the several rollers of 1 multiple cylinder will be rotated to lire required ini'zerest-number to the The journal or shaft 58- of thei 1terestlined) is l'orined its 2L "Ftllk, Fig. 8, free end cntt ing a. slot 50, formed in a, horizontal leyer-:uin 66, that fast on tucvertieitl rock v t is apparent that by rotating inol) 56 the levermrm 60 will be to the right or let t and that through its medii the 10Cl-Sl.1ijlt5l,1tS arms 5, and the scrcral gears 37, 38, and 39 will be shifted rigl'it or left.

its illu. rated in Fig. practically the salon construction, fil'lftllg merit, and combination o parts are employed for adjusting the i 255, 29, and 30 that engage and 30, before referred to. 7 end of each amount-rack is id d with a lateral er; e'iision or arm 61, 10b is journalr d s such arm, whose 0" enters a. slot formed in the free the resoe will be I end of :1 lever-arm '56, mounted last on a vert ill roots-shaft 67, t A? me being I)l'\')""l(l((l tli lever-arms (i3, 6i), and 70, that engage the several ltwlzing-rods .El of the several cylinde s A, B, and C. T11 by adjusting an or lower it may be on the adjacent e on the front of the casing l, and by rolnvi said l\.IlOl) the rm 66 may he H re o right or lcl t an uticrtl shalt 67 t :olry' rotated, so tl arms 68, 6?), and 70 shi, the several g-rods 3] correspondin llrercare :imoimt-lmob 64 higher set opposite any number rock-shafts 67,

one 1' mil amount-m (ill a cd i '1.

1 no n in Fig. Line \ZlOl) on the right 1S lil(ll( 2. ted by the nunurrstl 64, the next knob by 6 and thetlurd knob by 64- The numbers adjacent to the knot; 8:: indicate dollars from ten to ninety, inc

designated e, and the slot is tl'icrelore tens or ten' dollar slot. The 110:; slot is designated as the oneh1indrcd-dollur slot, since the nun1- hers 1 to 9 adjacent thereto indicate hundreds of dollars. Similztrly the third slot is termed the "one-thousnndmlollztr slot, since the numbers adjseent indicate thousmioisv it will he observed that the several interest and amount knobs are provided with poiirters or projections which are located ninety degrees sport. The serve to indicate the position to which the knob luis been rotated, itnd thereby the position oil the lever-itrms with which they connected, so that the operator may know Wl. positionit occupied by the several shifts ears Within the casing.

ilongwith the knob, and therel 7 lunch or t dred dollars. dK/ided into live spaces longitud itc forty-one spaces trsnsverii T one spaces corresponding slides 16 before LlCSCKlbBC.

roilr there will be ind cated in column toe interest on one in lor on 9. day at different rates of in te ing from three to seven per cent. 1 ti the spaces for the days and montl lJG readily observed orv understood stud 2 tlx amounts which the several used to indicate, numerals 1 to been applied alon i'ndi. rte days and i to indicate room to $900 are up Numbers have l rollers sull'iciel'i to indicate the se and it is not necessary th of interest slutll be indie As shown in iuountei'l on the toothed c x 'liuder 5 and with 21 corresponding goat? ranged at right angles to first on it horizontal slisl't through the front of the end i "ios it pointer or ens that t l y rotation ol the the crank 7 to the left or steal by m e .fl(l will he on u -msm peri i117 ilzzgl.

e numerals l.

ule the stuns )Il the left of tr, .e en opened to the.

for d l 0) the months. The p ion. posite the nunil ll mm t tir cylinder has be. to iudicatle (more? in opera the settir 11 the llzllel'vlz ll-t which interest X per cent he p1 incl six thousand so; hund em and the time eleven days ztnioont knob 56 and the ernoun 64 and 64 to be I ,ots in wliic v as Win in knoo 58 to Le pointer thereon p i number on. the lane pointer ornoinler i upward untilthe spur principal upon which ously when the rack is rotation of the knobto the left its crank-arm 58 (see Fig. 10) carries the lever-arm 60 to the left, and thereby rotates the vertical. rockshaft 54, so that its lever-arms 55 throw the geazs 39 (see Fig. 14) to the left, so that the lugs on the hubs of the several gears engage or look with the several master-gears 42, which form an attachment of each of the multiple cylinders A, Band C. Then as the interest-knob is shoved up its rack 36 will effect rotation of the several rollers of the multiple cylinders A, B, and C, the cylinders as a whole remaining fixed in position. Thus the turning of the knob 56 to the left connects the rack or setting device with the main gear 42, so that all the rollers of the three cylinders may be rotated simultanepushed up. The rotation of the knob 56 to the right or into the position shown in Fig. 1 will obviously shift several gears 39 to the light, and thereb release or unlock them all from the correspond ing master-gears 42. The next step is to rotate the left-hand amount-knob 64 to the left until the lower spur thereon points to zero on the adjacent scale. Then shove the knob points to "6, which indicates $6,000, this being the amount indicated by the first number of the given principal. Then turn the knob 64 to the right until the upper spur oints to 6 and leave itin that position. he second amountknob 64". is similarly operated to place it with reference to the numeral 6 on the 1 ight-hand scale, the number 6in this case indicating $600, which is the amount included in the interest is to be computed. Similarly the third knob 64 is adjusted with reference to the number 7 on the adjacent scale, this number indicating 5570, which is also included in the principal. Thus care must be taken to always 1otate the knobs to the left before shoving them upward and then to the'right after the knob has been placed opposite the numeral standing for thousands, hundreds, or other amounts included in the principal. From the foregoing descLiption it will be known that this adjustment of the knobs 64 64" 64 to the left and right throws the seve; al leverarms .66 in corresponding directions, so that through the rock-shafts 67 (see Figs. 11 and 12) the locking-rods 31 are adjusted to car; T the gears 28, 29, and 30 to the left and to unlock! the rod 31 from the'sp; ocket-wheels 12', 13, and 14 on the other ends of the multi lecyliifidershafts. When the parts are thus adjusted, the raisin r of the knobs will rotate the multiple cylinders as a whole. The thi. d and last step in the mechanical operation of the machine consists in rotating the (rank 7 in the direction of the hands of watch, so that the toothed cylinder 5 and the sprocket-wheel 10 on the shaft thereof are rotated in a direction of the arrow indicated in Fig. 3. The effect of this is to bring down a series of slides successively, beginning on the right and proceeding toward the left. The crank 7 is rotated until the pointer 74 on the dial 75 (see Fig. 1) is opposite the number 1 1, which stands for days. The several shutters 2, 3 and 4 of the th: ee slots in the font of the casing will now be open, and through the openings in the slides pulled down (see Fig. 18, Sheet 2) may be read the numbers indicating interest for the desired time at the given late on the numbers "6670. In the upper slot will appear $11, which is the interest on six thousand dollars for eleven days at six per cent, and in the second slot will a pear $1.10, which is the interest on six given rate and time, and in the third slot will appear 12 5-6 cents, which is the interest on seventy dollars at the given rate and time. Adding these several amounts together, it will be found that twelve dollars and twentyt'wo cents is the aggregate inter est on the enthe principal at six per cent. for eleven days.

In further explanation of the machine and its operation it may be stated that the interest runs in a spiral line on the cylinders, or, in other words, interest at a given rate increasing day by day is indicated in a spiral line around each multiple cylinder, so while interest for one dayalways appears in the first right-hand space on a roller for two days it appears in the second space on the next or succeeding roller, the third days interest on the third space of the next roller, the fourth days interest on the fourth space of the next roller, and so on around the entire cylinder spirally until the full capacity of the cylin der is reached. For example, the interest of one hundred dollars for one day at five per cent. is one and seven-eighteenths cents, which amount appears in the first right-hand space of first roller. The interest for two days is two and seven-ninths cents, and it appears on next or second roller one space to the left. Again, interest on one hundred dollars for one day at seven per cent. is one and seventeeneeighteenths cents and for two days it is three and eight-ninths, which amount is seen on second roller one space to the left.

The device on rack for setting the amount simply rotates the several rollers of a cylinder individually to bring to the front or the opening in the casing the first days interest on the amount. Then to obtain two days interest it is obviously necessary to rotate the multiple cylinder as a whole so that the second roller may be brought to the front, and this is done by the crank 7 and the chain. and sprocket mechanism 11 12 13 connected with it. The roller 5 is also rotated, and thus the secondslide 16 is pulled down so the two days interest appears through the opening. The three days interest is obtained in the undred dollars at the same way, the crankfivbeing turned until the pointer 4 on the time-dial the i; will have been "I and the cylinder have been rotote-d, so that the third. roller ruin the startinn-point will be :it the opening, and the three i "2st may then be read through the opening in the third slide.

To recapitulate, t e individunl rollers of each cylinder are first I rented i .d by rock .513 to indicate interc i lor one dcy for a given re Then the cylinders are rotated as a. Whole (the ind ividuol rollers remaining fixed on their es) to bring to the front a particular roller snowing amount of interest for a given time, 630. Thus it the interest is to be calculated on tour hundred dollars the lour-hundred-dollar roller is brought to the front, or opposite the opening: in the casing. This is done by means cl ruck so (see Figs. and gears 37 38 3t). The next and final step in the operation the rotation of the cylindcr by crunl: 7, chain 11, end 12, 13, and 1.4; end the pulling down oi the slides '16 successively until the required amount or amounts are visible at the front.

in order to restore thc machine to its origillll condition, the erenk 7 is rotated hockrd or in the opposite direction from the first rotation until the pointer 7 4- stands at l, indicated by dotted lines, 1, and the several {11I10L1l1t-lU10l)S are turned to the left quarter-round and then shoved down to the position indicated in Fig. 2 end then turned again a. quarter to the right. The interestlrnob 56 is also siini .irly manipulated.

For convenience out threeuuiltiple cylinders and their ttschincnts are illustrated in this case; but it is obvious that any other zest-er number nmy be em ployed, so that interest may be reckoned on any mnount from one cent to one i'nillion dc.

[is shown in Figs. 12,

l1, and J2, shutters its 3, prefers and ntt end o. the (1L constructed 0 echcd to rock-sl i ots and having crn'is reorwnrd or Within tl SllOWD. in. Fig. are c i re sheet metal .tedin the 77 {)l'OjGOhlllQ' casing. l the ti 1ocl 1-shetts (l lil "s as, and 27 oi' en tipi cylii ders d1 'i'erent distances standard .i, and each is provided crank '79, to ich n. vcrtioiiil rod. 330 is Tl'ius, as shown in Fig. Ill, there are three such rods, ell arranged shown in F1 1.? end pivoted. to a lever 81, fulcrumed lug at the bottom using 1. The three levers 81 are arranged under 1 in such rela- 1 to the amount-reeks that the letter strike upon their rear ends es the racks descend, thus closing the shutters, in Fig. l la.te-spring 82 norrnell -holds down the front end of each. such re ;1 lever 81, so that the scuttcrs are: open end are held. open 2 and 1. 0)- I Whenever a rcclr is raised, this being necessary to enable the operator to view the slides and note the nijimbers that appear in the slots of such slides as may bepulled down by the toothed. cylinder It will be perceived that if any one or" the nznoun t-l nobs--s ay 6 lis not raised the rack and shutter 2* that correspond to and are connected with it Will not be raised and opened, respectively. In brief, only the shutter or shutters are open through Whose slot or slots interest is to appear. Thus confusion is obviously avoided in reading numbers indicating interest.

As shown in Figs. 4, 14, and 16, a platespring 83 is applied between the disks 53 of the several multiple cylinders and the several master-gears 42 applied to'the some for the purpose of applying suflicient friction to the gears to prevent their rotation except when it is required to be effected in a positive Incnner. This spring is made in annular form, but provided with a lateral shank, Which is riveted to the disk 53. Thus it stands normnllyin the position indicated in Fig. 16 but when the several gears 39 are shifted to the left to lock them with the master-goers &2 the spring is compressed or forced into the recess in the disks 53, as indicated in Fig. 14:. As shown in Fig. fl, the outer side of the spring is roughened to increase its friction with the master-gears l2. The letter are held in place es to lateral movement by means of smell brackets or keepers 84%, which are ettechcd to the disks 53.

i l/hut I claim is 1. The improved machine for computing interest, comprising a series of rotatable multiple-roller cylinders, each roller thereof having inscribed on its periphery numerals indicating amounts of interest on sums varying Loin unity upward, the said numerals being arranged progressively on successive rollers, means for rotating the rollers individually, and means for rotating the cylinders as :1 Whole, eportured slides arranged vertically in front of the several multiple cylinders, and means for normally supporting and for pulling down the said slides to bring their operturcs into coincidence with numerals on indi viducl rollers of the multiple cylinders, sub-' the casing, and a rotatable cylinder provided with teeth adapted to successively engage the said slides, for drawing them down to bring their apertures in coincidence with the slots of the casing, substantially as described.

3. In a machine for computing interest, the combination of a series of'rotatable multiple-roller cylinders each roller of which is inscribed with numerals indicating amounts of interest for different times and at different rates on sums progressing from unity upward,

means fo'rrotating the rollers individually while the cylinders remain fixed as a whole,

means for rotating the multiple cylinders as a whole While the individual rollers thereof are held from rotation, for the purpose of setting;

the cylinders corresponding to the principal on which interest is to be reckoned, a casing provided with horizontal slots in its front portion, the same corresponding in number with the multiple cylinders and arranged directly opposite the axes of the cylinders, and means the combination of a series of rotatable multiple-roller cylinders, each roller thereof'having inscribed on its periphery numerals indif eating amounts of interest on sums varying;

progressively from unity u ward, means for rotating the individual rol ers for indicating interest at different rates on the different sums with reference to which each roller is inscribed, means for rotating the cylinders as a whole for setting them corresponding to the principal upon which interest is to be reek oned, a series of vertically-movable slides provided with apertures corresponding in number to the several multiple cylinders, a cylinder or roller arranged below the multiple cylinders and provided with teeth arranged spirally thereon for engagement with the slides successively, and means connected with such roller, and the several multiple cylinders for rotating them all simultaneously, in order to bring to the front the numbers indicating amounts of interestdn certain individual rollers, so that said'nufribers may be seen through the. openings of the slide or slides that may be brought down, substantially as described. I i

5. In machine for computing interest, the combination with a multiple-roller cylinder comprising a series of rollers duly inscribed with numerals indicating amount of interest on diiieren't sums progressing from unity upward and accordln to diiierent rates and time, each ofsaid ro lers being provided with a spur-gear, a mastengear arranged within suc r spur gears and meshing therewith,

gear for the purpose of rotating and setting the individual rollers to indicate interest at different rates for a given time, spur-gears mounted on the shafts of the respective mulmeans for imparting rotation to such mastertiplecylinders, and means connected therewith for rotating such gears for rotating the multiple cylinders as a whole for the purpose of setting said cylinders corres ondlng to the amount of the princi al on w ich interestis to be reckoned, sproc ct-wheels arranged on the opposite ends of the multiple-cylinder shafts, a sprocket-chain running thereon, and a driving sprocket-wheel by whose rotation the several cylinders may be rotated as a whole, for bringing to the front for inspection numerals on the rollers which indicate the re quired interest, substantially as described.

6. The combination with a multiple cylinder comprising a series of rollers arranged concentricall and having inscribed thereon numerals indie sums varying from unity upward for different times and at different rates, a shaft supportng such cylinder, a master-gear mounted concentrically thereon, and a series of spur gears or pinions fixed on the extended shafts of the several rollers and meshing with such master-gear,,a spur-gear mounted slidably on the shaft ofthe cylmder'and adapted to be locked'with the master-gear, means for rotating such slidable. gear to impart rotation to the master-gear and, the pinions meshm therewith whereb the rollers may be rotate and set individuallycorresponding tothe interest, substantially as described. 4

ating amounts of interest on 7. The combination with a multiple-roller cylinder, comprising a series of concentric rollers each of which is inscribed with numerals indicating amounts of intereston amounts varying progressively from unity upward-ea series oi pimonsfixed on the journals of the several rollers, a master-gear arranged con.- centrioally with such pinions, and the shaft of the multiple cylinder, a spur-gear which is slidable on the cylinder-shaft and adapted to lock with the master-gear which is loose on said shaft, a vertical rack-bar which engages such slidable spur-gear, means for adjusting said rack vertically according to a scale indicating varying rates of interest, and means for shiftin the slidable spurear for looking it with and releasing it from t e mas'ter-gear, substantially as described.

8. T he combination with a multiple-roller cylinder, comprising a series of concentric rollers, each inscribed with numerals indicating interest on sums varying progressively from unity upward and at different rates and times, pinions mounted fast on the journals of the several rollers, a master-gcar which is concentric with said pinions and the shaft of the cylinder and adapted to mesh with the pinions, a spur-gear arranged s'lidably on the shaft of the cylinder and adapted to lock with c scvc al j ust. U

and mam curred Zn 100?: i le "mm Li s, czicli comprising :i,

r m'mngcil concenmcally nscrilmd on their peripheries nu- :ind ha i w i mel'als lIMllCI )g' amounts or interest on wk 7 with the several pi'ii ciiis and Jmn (.1 con- '81'1LTlCLll on shaft of the multiplc cylin- (iv/ a siirlul adapted to lock with such i)21Sl Ci-g0iiil l J1 imparting rotation 0 all the lOl'S si muliancously, vertical rack-liar cnring the series 01" sliclahlc gears, a vertical laying levcr- DIS loosely c0niicctccl with the veizzl siulahlc snuigcms, mid a lower lave Wyn) also iixcil oil the i i Mi rock-s1 il and vc'i'ticall J-slidahlc itnob connected with the icl cl; and hcvhig a =2 crank poytvioii adapted to cngc ith the lower lever-arm of the rock-Sim i whcrchv the rotation of said knob cl'l'ccts the s'iiiitin g of thc id his; s iny-gears with re cc hi) M nmstw ccuand its vertical ad juncnlx crts the union of the s vcyzil roll-91's 0f the multiple cylinders, rcquiiczl to C-OITJ- spoml with ihc dii'l'cic li/l'fltilSOl inlci'csit, sub slxziii'tizii us ilescril'icil O. The combinaticn with niultiplcq'ollcr did 31's, cach comprising 21- scries 0i rollers (l concciil-rically' an having inscribed n nulnei's indicating mm'ui'nts of in- )i: an: in from unii y' upward and iiOLllS lci iomlinv" i ML indiviimil iiccorcing to ii nch intci'ckis in )c cciiiputcv', mounl' i ()11 ch slim cl a mail-- rci'iiicni 121 i 221125. the Sillll 'iily m: ji'cqui lc c l ru c'i's chi": Qgii 'ili ASVCF'" 1i) cach f the and am icc l'nr ioi v 'ng rho ml- I (2' c0 luck and iclc the spur the E'OliEIS ind i ticulai' mic 0i i on the shafts ol' t i'ually con pond ing in paw "cst, Splii' (z is moun lcil multiple cvlindcrs, movable cviccs adapted to any he s i l gears for :iltci'imtcl iicliing them fliili c mnltipic cylinccrs viewing lhcni Lhc'ich' 11i, vertical rm: IS 0 pm'uing in. number with the SGVQiill cylin I'MFi, and adapted in cngagc the rcspcctivc j, c:.,1'.-;, a. v'fi'tical I'OCi-ishaft having :i ics of arms ifiziptez to (U- gage with the hacking devices of the scvcml s' ur-gcnrs, a lLV-fi'tl' lOVQf-Mifi 'fiXcil on such rock-shaft and im'ving a VOIU nil slot in its free and, vc 'ticnlly idnblc (lo/vices permanently attached ii ii lcvcr-mms oi the HOV- eml racks, and iii'laptcd to cri gc the Lhc rim! shaft im. shifting I l lci't, ivhmchy thc nicks ci'Li Hill; wrcording to the amounts of Lhi principal in millions, thousimc's, hunsln-x' I .,m1(l the rock-shaft may be rotated for luclcing and i'clciisii'ig the spurgciu's pm iu'ntm v' L0 and lbllmvii g the 0pmation 0f lilic l'iiCi-lrl, ihstmiiiinll as (lescribcd.

Ii 24 The combiimtion with LL scrics of rank ciplc cylii'i lci's, czicll ciimpi'ising a scri is of rollers a'i'rzi'ngcfl ccni'tcnl; 1} anal inscribed on thcii pci'ipli s with m. ci'nls inzlicnit ZiIDOUIHIS of on sums v2 from unity upwzu'iii mm at (liiici'cnt mics l ci'cnt times, hollow i'utnmililc elm which the ylindcrs proper :1!- ported, mcnns it T chc roilci scvcml cylinders; ii'iili'viiluz to a particular mic (if in.

l at one and of thc St) rotating them as wnolc aiinount of thc pi Apili on which ink to hc ccii'ig'i'ii'tcd, minim a1 the simu- 7 may be aii usl'i pcsi'tc 2159 of the cylinrlcia-i as a WDOlO zmii'mspcmiir which intci'cst is to be com .ing device cxtcnrling' shafts of lahc FEW Grill (fifflli'liilf to incl; and release :iltci'mi means 3?."131 gcil at the upped indci's, siibstziintially as ilcviv .i liple c low shyifts proper mm P 11-,6H1S mountcl on he and of thc cylinders, nicks engaging the) saxnc for rotating the gears, sp10cl(cl1ii'l'iccls m rziigcl on the oppoc and means cnc them, a rod 21 and disengage from the said spur-gears and their s n'ocket-\vheels, whereby the spu r-gears are l()(l\'(-(l when the s roclwt-wheels are re leased and viceversa, substantially as (escribedv .l-t. 'lhe combination with a series ol' multiple cylinders, each comprising nine rollers arranged concentrically and having inscribed thereon nunmrals indicating amounts ol interest on sums varying progressively from unity upward and at di'tl'erent rates to! (it'- l'erent times, means l'orrotatingand adjusting the indivii'ual rollers correspomlingto a particular rate ot' interest, means for rotating the cylinders as a whole cin'responding to the amount of the principal on which interest is to be computed, means arranged at the opposite eins ot' said cylin'lers for rotating them as a whole, eorrespon ing to the time at which interest is to be computed, and a movable. indimttor (anlnectml.with such means and actuated thereby for indicating on a dial the time for which interest is to beeomputo l, substantially as described.

15. 'lhe combinationwith a series of mul tiple-roller cylinders, each comprising a series of n ne rollers arranged concentriiatlly and inscribed on their peripheries with numerals indicating amounts oi interest on sums varying progressively t'rom unit-y upward, at ditl'erent rates and for ditl'erent times, means t'or adjusting the. rollers individually according to a particular rate ol' interest, means for adjusting the multiple cylinders as a whole corresponding tothe amount ot' the principal on which interest is to be computed, a series of verticallyanljustable slides arranged in l'ront ot' the several multiple cylinders and proyidcd with apertures corresponding in mnnber with the cylinders, a rotatable roller arranged below the several cylinders and provided with teeth arranged spirally and adapted tor engagement with the several slides, means arranged at the opposit-e ends of the cylinders for rotating them simultaneously according to the time for which interest is to be computed on the entire principal, such means being connected with the toothed cylinder, a casing provided with a scale indicating days and months, an

I index or pointer adapted to rotate. over sa d scale, and means connecting it operatively with the toothed cylinder whereby it moves in unison with the litter, substantially as described.

l6. 'lhe combination with a series of multiple cylinders comprising rotatable rollers arranged conci ntrically and inscribed as set forth, ol" gears optaatively connect-ed with the several rollers l'or rotating the latter, the rack-bar adapted to engage the several gears, means for shitting the gears for engaging them with and disengaging them from the rollers, a knob provided with radial spurs set ninety degrees apart, and connected with the aforesaid rack, and lneans lor shitting the spur-gears, the said spurs serving as means to indicate engagement or disengagement ol the gears, substant ally as described 17. 'lhe combination with a casing having a slot in its tront portion, of a multiple cylinder comprising a series ol' concent i rollers each inscribed with numerals indicating amounts of interest on sums varying pro gressively trom unity upward, at ditl'erent times, and at ditl'erent rates, a verticallymovable slide arranged between such cylinder and the casing and provided with an aprture, and means l'or adjusting the sa d slide and cylinder to bring the front ot' one ot the rollers in co ncidence with the slots ot" the slide and easing, substantially as described.

is. The combination w th a multiple cyl inder, compr s ng a series oi" concentric rollers each inscribed with numerals indicating interest .on ditl'erent sums, l'or dill'erent times at di tl'erent rates, ot a series of slides arranged vertically and provided with apertures, levers withwhich said slides are connected, means For normally supporting the slides but permittingtlwm to y eld to be drawn downward, a rotatable cylinder arranged below said levers and provided with teeth arranged spirally, and catches pivoted to the levers and adapted for adjustable engagement with the teeth ol the cylinder, substantially, as described.

it). The combination, with a series of multiple cylinders, having their axes arranged horizontal in the same vertical plane and each comprising rollers having inscribed on their peripheries numerals indicating amounts of interest on ditl'erent sums, at ditl'erent rates, 'or ditl'erent times, ol' means t'or rotating the rollers iinlividually according to a particular rate ol' interest, a casing inclosing said cylinders and provided in its t'ace with horizontal slots corresponding in number to the cylinders and arranged in the same horizontal plane with the axes of the cylinders, means for rotating the cylinders as a whole according to the principal on wh ch interest is to be CUlllPHtOtl and also according to the time for which interest runs, a series ot' vert wal slides arranged between the cylinders and the front ol' the ca ing and provided with apertures, means l'or elastically supporting the several slides, a. cylinder arranged below the multiple cylinders and provided with teeth arranged spirally, devices connected with the slides and having catches adapted to engage the teeth ol the lower cylinder, and a stop which such devices engage when released from the cylinder, substantially as described.

20. The combination, with rotatable cylinders Waging rollers inscribed as specified, and means for rotating the rollers individually and the cylinders as a Whole corresponding to the rate of interest, the amount of the principal, and the time forwhieh interest is grooves adapted to receive such flanges, and

'within the c ime therewith, spa incun the sliaits oi tie multiple computed, of tootlie J low the multiple yin airsngerl between th- I thejront of ezl. t0 the free end to engage tne re 3 Lot: i i r s s uigs pres "atcnes lei 110i them in t said catches bein sides with sir #15 the levers and sl lv 01 shoulders, which, e drawn down, upon the peripl the toothed and disengage the catciies ire-in the i2 substantially described.

v 21. The combination, with casing its front slotted, of a series of miiltip cylinders, haying their component IOll scribed as and for the purpose specified means for adjusting the said cylinders and their individual rollers corresponcliirto tile amount of the principal, rate of and the time for which the ttcr is COED. putecl, a series of expert/tired slii ari between the multiple cyliii ers and the of the casing, the slides being'const with parallel Vertical flanges on their sides, and the casing provided with vertical means for drawing down the slides suecessively; substantially as described.

22. The combination, with casing having its front slotted, of a series of rotatable multi le-roller cylinders, having their indiviiinsil r0 lers inscribed as set forth, means for eiljusting the individual rollers and the clers as a Whole corresponding to the interest, the amount of the pri; time for which interest is to be series of vertical apertureil between the multiple cylinde. of the casing, means for (ire several slides successively, nectecl with the upper Clidn o with a iizred portion cftlie can a slides are normal ly supported elastic stantially described.

v 23. The combination, .Vltll tl roller cylinders, coinprising a centric rollers-parallel disks 1: t are journalecl, each roller imin Witinumerals i" sting llilUL est on sums var; pro from H, upward, diiie cnt ciilei'ent oi pinions fixed on t a master 

